<!DOCTYPE html>
<style>
    .box { display:inline-block; width:1em; height:4em; background:blue; }
</style>
<p>There should be a blue square below.</p>
<div style="line-height:5em;">
    <br>
    <div style="display:inline-block; width:1em; width:4em; height:4em; background:blue;"></div>
</div>
